The present invention relates to a facsimile communication system, in particular, relates to such a system in which the group 3 facsimile signal is transmitted through a digital transmission line by conversion of a tone signal, a binary signal and a picture signal to digital form.
Conventionally, a group 3 (G III) facsimile signal is transmitted through an analog telephone line with 4 KHz band, or a digital line with 64 Kbit/s rate using a CODEC which convert an analog facsimile signal to a digital PCM signal.
However, said digital transmission system using a PCM code has the disadvantage that it needs 64 Kbit/s of Bearer rate, although the G3 facsimile signal has only a slow data rate of up to 9600 bit/s. So, the efficiency of the transmission line is not being fully utilized.